1. Field of the Invention
The present invention relates to a steering device in which play of a bolt shaft and the like during telescopic adjustment can be prevented using a telescopic adjustment function enabling a driver to adjust a position of a steering wheel in a front-rear direction.
2. Description of the Related Art
A variety of steering devices equipped with a telescopic adjustment mechanism are known. A typical structure of such a steering device includes a fixed bracket mounted on the vehicle body and a movable bracket supporting a column pipe, and the telescopic adjustment by which the movable bracket and column pipe can be moved or fixed is performed by loosening or tightening the fixed bracket.
Therefore, where the play of the steering wheel is present during such telescopic adjustment, good telescopic adjustment feel is lost. Accordingly, various means for preventing the play during telescopic adjustment have been developed and implemented. Japanese Patent Application Publication Nos. 2009-143299 and 2006-240327 represent such related art.
Japanese Patent Application Publication Nos. 2009-143299 and 2006-240327 are briefly described below. In the explanation of Japanese Patent Application Publication Nos. 2009-143299 and 2006-240327, the reference numerals are placed in parentheses to distinguish them from those in the explanation of the invention of the present application. In Japanese Patent Application Publication No. 2009-143299, as shown in FIG. 3 thereof, the spring (47) that impels the eccentric cam (46) and bolt (41) upward is provided, thereby causing the guide pieces (48, 48) to slide in the front-rear direction, while being pushed against the upper side of the telescopic elongated holes (23a, 23b) as shown in FIG. 3. As a result, no play occurs during telescopic operation.
With such a structure, the play of the eccentric cam (46) that is in direct contact with the spring (47) can be removed. However, the play of the bolt (41) disposed inside the eccentric cam (46) cannot be removed. This is because the bolt (41) is configured to be assembled by insertion into the eccentric cam (46), and a certain gap should be present between the eccentric cam (46) and the bolt (41) to enable the insertion of the bolt (41).
Since the gap is present, even though the eccentric cam (46) is impelled upward by the spring (47), the play between the bolt (41) and the eccentric cam (46) can be removed. Therefore, in the configuration described in Japanese Patent Application Publication No. 2009-143299, the play occurring during telescopic adjustment cannot be completely removed.
Further, a steering device is also known in which telescopic adjustment is performed from a different standpoint. Thus, a telescopic elongated hole is provided in a bracket portion, a bolt or the like is disposed so as to pass through the telescopic elongated hole, and the bolt is moved along the shape of the telescopic hole, thereby moving the steering wheel in the front-rear direction. In this case, where the bolt is moved to the initial end portion and final end portion in the longitudinal direction of the telescopic hole (telescopic operation limits), the problem is that since the end portions of the telescopic hole and the bolt are made from the same metal, metallic sound is generated when the two collide, and operation quietness and operation feel during collision (at the telescopic operation line) are lost.
In the configuration described in Japanese Patent Application Publication No. 2006-240327, the collar member (14) shown in FIG. 2B is pushed upward by a V-shaped spring shown close to the center of FIG. 2A. As a result the play is unlikely to occur during telescopic operation. In the configuration described in Japanese Patent Application Publication No. 2006-240327, the protruding portion (11) of the stopper buffer member (C) is inserted into and mounted on the fixing hole portion (6) of the attachment member (B) fixedly attached by welding to the steering column (4).
The stopper buffer member (C) is mounted to be positioned at both end locations in the longitudinal direction of the elongated hole (3) for adjustment, and the shaft portion of the bolt (13) abuts on the stopper buffer member (C), without abutting on both ends in the longitudinal direction of the elongated hole (3) for adjustment. As a result, the longitudinal end of the elongated hole (3) for adjustment and the shaft portion of the bolt (13) do not come into contact with each other and therefore no metallic sound is generated and good quietness and operation feel are maintained even when the components collide.